A sensitive drum incorporated in a transfer type electrophotographic reproducing machine is mostly of the type, in which a cylindrical drum surface is applied with a photo-conductive material due to evaporation. The surface of the photoconductive material of the sensitive drum is cyclically and repeatedly sugjected to the charging -- exposure -- developing -- cleaning processes. In the cleaning process, the surface of the photoconductive material is subjected to the erasing, followed by removal of residued toner by means of a brush or web, therey being put in a re-usable condition.
The repeated use of the sensitive drum for image transfer incurs deterioration in a photoconductive materials, resulting in the lowered charging characteristic of the photoconductive material. For restoration of charging characteristic of the photoconductive material, the cleaning of surface of sensitive drum must be periodically effected by an operator.
Hitherto, the cleaning of the sensitive drum has been effected by withdrawing the sensitive drum outside of the reproducing machine. This is accompanied by the lowered workability in the cleaning as well as by a risk of breaking the surface of sensitive drum when the sensitive drum is demounted from or set to the reproducing machine.